Strange power/throttle response :454 burb

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Mildphil

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Can you log fuel trims? It should throw a code if they're way off.. but it sounds like you're lean as all hell or maybe its misfiring? Check your cap and rotor?
I have no codes or CEL. On torque my Air to fuel ratio is commanded by the ecu at 14.7:1, so everything looks good unless if something else is causing it to run lean (if that's the issue). What should I look out for on the cap and rotor?
 

JavaMan

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The fuel trims are different from commanded air fuel ratio.
The fuel trims show how the injectors are working to achieve the commanded air-fuel ratio.
 

Christian Steffen

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I have no codes or CEL. On torque my Air to fuel ratio is commanded by the ecu at 14.7:1, so everything looks good unless if something else is causing it to run lean (if that's the issue). What should I look out for on the cap and rotor?

Yeah - if your fuel pressure is low or something your o2 sensors will try to make up for that by adding fuel via the trims.. Knowing what the o2 sensors are doing would help a ton.

On the cap, look for cracks, corrosion, etc. Anything that could interrupt spark. Same on the rotor.
 

Mildphil

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The fuel trims are different from commanded air fuel ratio.
The fuel trims show how the injectors are working to achieve the commanded air-fuel ratio.

The fuel trims should throw a code.. cap/rotor issues might not

Thank you for the help. I'll see if I can view the fuel trim in torque and I'll check the cap tomorrow. Any of you two ever experienced an issue like this before?
 

Mildphil

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Here are my numbers while driving around my neighborhood. Top speed I hit was 45 mph. There were all taken as I was driving, with the first one being parked.

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honkon

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Fuel trims don't look suspect to me. Sounds a lot like torque converter shudder. Have you paid attention to the TC slip rpm while it's shuddering? It will increase while shuddering if the TC is the issue. It is strange that it would be happening at all speeds though.
Misfires are more of a bucking feeling than a shuddering.
I have a Mountaineer with the 4.6 3v/6R60S that does exactly what you described on the interstate. Shudders every few seconds. It's a TC issue.
 

Mildphil

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Fuel trims don't look suspect to me. Sounds a lot like torque converter shudder. Have you paid attention to the TC slip rpm while it's shuddering? It will increase while shuddering if the TC is the issue. It is strange that it would be happening at all speeds though.
Misfires are more of a bucking feeling than a shuddering.
I have a Mountaineer with the 4.6 3v/6R60S that does exactly what you described on the interstate. Shudders every few seconds. It's a TC issue.
It does it almost constantly on the interstate, but yesterday it didn't do it at all when I recorded those trim values. Does your mountaineer feel rough at stop lights too?
 

Mildphil

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i googled TC shudder and this is what I found.
"Driving about 45 MPH there is a sudden shudder in the vehicle. It almost feels like running over a rough spot in the road or a cattle guard. As quick as it appeared, it is gone, until the next time it occurs."
This is EXACTLY how it feels on the highway, like I'm running over those rough cuts in the highway shoulder.
 

Mildphil

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I took screenshots of torque with the TCC. in a few pics, no shuddering was happening. I also noticed that the shuddering did not change the TCC rpm at all when locked, as all the photos with the TCC rpm nearing 0 rpm were when it was shuddering. I did notice that one ot begins to shudder, it will shudder at any speed, TCC rpm unaffected. I just parked and the truck felt like it was going to shake itself to death even though it was in park (same amount of shuddering when driving). I have yet to check my cap yet, which I will do now.

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